I have a '99 E200 that has never had a problem until last month, when it refused to start. The engine turns over but doesn't start. I had it taken to the garage where they replaced the fuel pump and filter. It worked for a week then had the same problem. 2 more trips to the garage and they couldn't find anything wrong. Still refuses to start about once a week. Any ideas?

I had the same problem a couple weeks ago and I ended up changing the CPS (crank position sensor). Rule of thumb, cold start problem - CAM sensor, warm start problem - CPS.

It's been a week for me without a problem. Part is about $50-80 depends on where you got it from.

Good luck.